I know the first televised political ad in the United States was the "We Like Ike" one during Eisenhower's election campaign. What was the first consumer advertisement, i.e. what was the first TV advertisement intending to sell a product or a service for people to purchase?
The first advertisement was in 1941, for Bulova Watches, before a Phillies-Mets game. However, the source notes that it was the first legal advertisement, perhaps implying that there were perhaps earlier advertisements prior to advertising being approved by the FCC, before TV regulation had matured.